Thread-cutting mechanism for sewing machines



F. W. OSTROM AND I. F. WEBB.

THREAD CUTTING MECHANI8M FOR SEWING MACHINES. APPLICATION FILED FEB. 1a.1918.

' l,%38,54:8. Patented Dec. 12, 1922.

2 SHEETS-SHEE] I.

2 67 f f Z7- 6 dam INVENTOR I I 3 b I 57544311050? BY O m YTTORNEY F. W.OSTROM AND I. F. WEBB.

THREAD CUTTING MECHANISM FOR SEWING MACHINES APPLICATION FILEDFEB-16,1918.

1 %38,5%8, Patented Dec. 12 1922 2 SHEETS-SHEET 2.

ATTORNEV Patented Dec. 12, 1922.

STATES FREELAND W. OSTROM, OF NEWARK, AND IRVING F. WEBB, 0F ELIZABETH,NEW

JERSEY, ASSIGNORS TO THE SINGER MANUFACTURING COMPANY, A CORPO- RATIONOF NEW JERSEY.

THREAD-CUTTING MECHANISM FOR SEWING MACHINES.

Application filed February 16, 1918. Serial No. 217,471.

To all'whomit may concern:

'13s it known that we, FREELAND W. Os- TROM5 and IRVING F. WEBB,citizens of the United States, residing, respectively, at Newark, in thecounty of Essex and State of New Jersey, and Elizabeth, in the county ofUnion and State of New Jersey, have invented certain newv and usefulImprovements in Thread-Cutting Mechanisms for A further object of thisinvention is to provide a continuously operated threadcutter adapted tosever the thread, extending from a sewed article, at the work side ofthe cloth-plate.

The invention has for a still further object to provide a continuouslyoperated thread-cutter with means, to positively direct the threadextending from a sewed article into the path of operation of saidthread-cutter.

Other objects of this invention will be apparent from the followingdescription and claims.

In its preferred embodiment, the present improvement comprises athread-cutting mechanism substantially as disclosed in the U. S. patentto Albert Rontke, No. 1,156,821, October 12,1915 but having continuouslyoperated connections with the actuating mechanism of the sewing machine.The cloth-plate of the sewing machine is provided with an openingthrough which the thread-cutter is projected in its operating movements.Bridging said opening and extendin in the direction of feed are raisedworkirecting members adapted to divert the stitched article out of thepath of movement of the thread-cutter, but permitting a spring-pressed,chain-directing member pivotally supported by the resser-foot to directthe thread extending from said article into the path of movement of thecutter, which severs the thread at the work sideof the cloth-plate as inthe Rontke construction referred to.

The present improvement is particularly adapted for use in connectionwith filled sack-sewing machines, but it is apparent that its use is notlimited to that class of machines inasmuch as the thread will bepositively directed into the path of movement of the cutter regardlessof the plane in which the sewing machine cloth-plate may lie.

In the accompanying drawings, Fig. 1 is a front side elevation of afilled-sack sewing machine of earlier construction, partly broken ofl:'and embodying the present improvement. Fig. 2 is an end elevation,partly in section, of a portion of the sewing machine, illustrating theeffective position of the thread-cutter mechanism and in dotted linesthe position of the ch,ain-directing member during the passage of thesack thereunder. Fig. 3 is a rear side elevation, partly in section of aportion of the sewing machine and showing the actuating means for thethread-cutter blades. Fig. 4 is a perspective view of a portion of thesewing machine cloth-plate and including the material-diverting bridge.perspective view of the chain-directing member. Fig. 6 is a fragmentaryview illustrating a portion of the autom'atic seamcontrolling mechanismfor the sewing machine as viewed in the direction indicated by the arrowA in Fig. 1.

The filledsack sewing machine illustrated comprises a base 1 from whichrise the vertical standards 2 and 3 supporting the table 4. Mounted uponthe table 4 is a bracket 5, carrying the overhanging sewing machine head6, having stitch-forming mechanism of wellknown construction andincluding a needle 7. The cloth-plate '8' of the sewing machine isprovided with a throat-plate 9 having a feed-slot 1-0 traversed bythefeeddog 11, secured upon a feedbar 12, pivoted to the feed-rocker 13,actuated to impart feeding movements tothe feed-dog by means of a pitman14 from an eccentric on the Fig. 5 is a messes ing wires 26 and 27, thethread-cutter becomes effective to sever the chain as heretoforedescribed. After the stitched sack rides past the end of the'trip-bars49, the latter assume their raised position under the reverse action ofthe belt-shifting weight 63 thereby stopping the operation of the sewinmachine.

I-Iaving thus set forth the nature of the invention, what we claimherein is 1. In a filled sack sewing machine, the combination with acloth-plate, stitchforming mechanism includin a reciprocating needle,and feeding mec ianism including a feed-dog with actuating means forsaid mechanisms, of a thread-cutter operatively connected with saidactuating means, and a cutter-guard projecting outwardly from saidcloth-plate substantially in the direction of reciprocation of theneedle to direct the sack mouth outside the field of cuttenactuationrearward of the point of seam-formation.

2. In a filled sack sewing apparatus, in combination, stitch-formingmechanism, means for conveying a filled sack past said stitch-formingmechanism, automatic controlling means for determining the period ofoperation of said stitch-forming mechanism, a thread-cutter having apath of operation intersecting the plane of the sack mouth at the pointof seam-formation, means for continuously operating said thread-cutterduring the period of operation of said stitch-forming mechanism, andmeans for diverting the stitched sack mouth out of the path of operationof said thread-cutter.

3. In a filled sack sewing machine, in combination, stitch-forming andfeeding mechanisms, a cloth-plate, a thread-cutter having a path ofoperation substantially at right angles to the line of seam-formationand its effective cutting position on the, work-side of the cloth-plate,means for continuously operating said thread-cutter, and means 'fordiverting the filled sack mouth out of the path of operation of saidthreadcutter and permitting the latter to sever the sewing-threadextending from the stitched sack.

4. A sewing machine including in combination, stitch-forming and feedingmechanisms, a cloth-plate, an opening in said cloth-plate in the rear ofthe stitch-forming mechanism, a thread-cutter comprising a pair ofmovable cutting blades having an operative path of movement through saidopening intersecting the plane of the article being stitched at thepoint of seam-formation, means for continuously operating saidthread-cutter, and means for directing a stitched article out of thepath of movement of said thread-cutter.

5. In a filled sack sewing machine, the combination with a cloth-plate,stitchforming and feeding mechanism, and means for actuatingsaid-mechanism, of a threadcutter having a path of operationsubstantially at right angles to the line of seamformation, means foroperating said threadcutter, and. a yieldingly mounted threadchainpositioning member having a threadengaging portion located at the rearof the rearward limit of feed-movement of the feeding mechanism forpositioning a thread chain below the plane of said cloth-plate to beengaged and severed by said thread cutter. v

6. In a filled sack sewing machine, the combination with a cloth-plate,stitch forming and fabric feeding mcchanism,and actuating means for thelatter, of a threadcutter having a cutting portion operative above theplane of said cloth-plate and operatively connected with said actuatingmeans, and a thread-chain positioning memher for positioning athread-chain below the plane of said cloth-plate to be engaged andsevered above the latter by said threadcutter.

7. In a filled sack sewing machine, the combination with astitch-forming mechanism, a fabric feeding mechanism, a presser-foot,and actuating means for. said mechanisms, of a thread-cuttteroperatively connected with said actuating means. a thread-chainpositioning member provided with a thread-chain guiding surface andhinged to said Presser-foot, and means for directing a filled sackoutside the field of cutter-actuation, said chain-guiding surface,directing means and thread-cutter being located at the rear of therearward limit of feed-movement of the feeding mechanism.

8. In a sewing machine, the combination with stitch-forming and feedingmechanism, of a thread-chain positioning member having movements invadirection substantially transverse to the plane of the fabric beingstitched, a thread-cutter, and means for actuating the thread-cutter tosever a chain of thread. said thread-cutter actuating means includingdevices for imparting to the thread-cutter movements in a directionopposed to said movements of the thread-chain positioning member totighten said chain during the severing of the same.

In testimony whereof, we have signed our names to this specification.

FREELANI) W. OSTROM. IRVING F. WEBB.

